This invention pertains to the art of fasteners for structural members and, more particularly, to retaining means for such fastener members.
The invention is particularly applicable to a retaining device for nuts utilized in conjunction with strut-type structural members and will be described with particular reference thereto. However, it will be appreciated that the invention has far broader applications and may be employed for other purposes and/or adapted for use in other environments.
So-called strut-type or apertured structural members have been known and used in the art for many years. The structural members themselves are comprised of elongated channel elements having generally U-shaped cross-sections. In addition, a pair of inwardly-turned flanges or shoulders extend along the outer terminal ends of the channel element legs to define bearing seats for supporting loads. Typically, these structural elements are employed as struts which are sometimes cast in concrete or used as columns, cross-members, and so on in the construction of storage racks and the like. Also, they may be used to form simple support members for hanging other structural elements.
In many applications, a threaded fastener or a nut is received in the structural member channel for use in interconnecting the structural member to other members or elements. In that case, the fastener head or the nut has a generally rectangular configuration so that it may be inserted into the channel between the two inwardly-turned flanges or shoulders and thereafter rotated approximately 90 degrees so that the head or nut will engage the underside of the flanges. Because of the general conformation of conventional strut-type structural members, it is desired to provide means for locating and retaining threaded fasteners and/or nuts in a desired position therealong.
Heretofore, several alternative retaining means have been proposed and used. For example, U.S. Pat. No. 2,345,650 to Attwood discloses use of a coil spring interposed between the mechanical fastener head or nut and the bottom wall of the channel so that the head or nut is continuously urged toward engagement with the underside of the inwardly-turned flanges or shoulders. U.S. Pat. No. 3,493,025 to La Londe, et al. shows another type of attachment or retainer device comprised of a flanged retainer means cemented to the upper face of a nut for frictionally engaging the channel flanges or shoulders. Finally, U.S. Pat. No. 3,483,910 to La Londe, et al. shows a spring type device associated with the upper face of a nut member adapted to cooperate with the inwardly-turned flanges or shoulders of a channel element to perform a nut retention function.
While the foregoing examples of prior retaining devices have generally performed as desired, each has certain structural or operational shortcomings which detract from their use. For example, these prior devices require that special retaining grooves or the like be machined or otherwise formed in the fastener heads or nuts for accommodating special connecting means associated with the retaining devices. The necessity for machining or forming such retaining grooves or the like added production time and costs to the overall assembly. Moreover, the necessity for using special connecting means added further manufacturing time and costs. In the case where retaining devices were cemented to associated nuts, the cementing process required that a period of time to be alloted to cement curing. Further, and because installation of the fasteners and nuts into the channel of a structural member requires that they be rotated approximately 90 degrees to effect retention, spring-type retaining devices may place residual biasing forces on the fasteners and nuts, tending to rotate them from the desired located position.
It has, therefore, been considered desirable to develop a new and improved retainer for mechanical fasteners and fastener receiving members. The subject invention is deemed to meet these needs and successfully overcomes the foregoing problems as well as others. The subject new retainer is relatively inexpensive to manufacture and is readily installable in a fixed relationship to an associated fastener or fastener receiving member. Still further, the new retainer is adapted for use in a wide variety of different applications and/or environments.